Endocrine Abstracts

JOINT2916

Current WHO guidelines consider that under an adequate iodine intake < 3% of the newborns (NB) should have TSH levels of > 5 mU/l at screening. The neonatal TSH screening was implemented in 1993. A new National Program focused on sustainable elimination of iodine deficiency disorders took place in 1994 and universal salt iodization for the whole country became mandatory. According to ICCIDD criteria Bulgaria was declared as “Iodine sufficient” in 2007.

Aim: To analyze the age-adjusted TSH distribution and provide actual data connected to the iodine intake in NB‘s between 2021-2024.

Material&Methods: Data from 177 607 NB (84.37% of all screened NB) aged 3rd-5th day of life were analyzed by TSH (DELFIA^R Perkin Elmer) in dried blood spots from 28 Bulgarian districts (107 maternities) between 2021-2024. Results: compared to 2006/2007 (2.8% of NB>5 mU/l) the proportion of NB with TSH>5 mU/l increased to 6.18% between 2021-2024 for the entire country. According to the TSH cut off 5 mU/l only one district was completely iodine sufficient during the entire period. Other districts showed fluctuations between sufficiency and mild iodine deficiency. Therefore the neonatal TSH distribution corresponds to mild iodine deficiency.

Conclusions: The neonatal TSH monitor was implemented as a constant part of the complex iodine monitoring program early at national, regional and hospital level. Despite a lot of factors influencing the TSH distribution, targeted actions are now necessary in order to proof and further evaluate the alarming situation of mild iodine deficiency appearing again in the country in the NB’s as the most sensitive and vulnerable population for development of mental deficits.